1. Field of the Invention
The present invention relates to a communication apparatus that executes a service with another communication apparatus using radio communication, and in particular relates to a communication apparatus that, in the case where device information has been acquired from another communication apparatus using proximity communication, and the execution of a service over radio communication has started, realizes the detection of the disappearance of another communication apparatus.
2. Description of the Related Art
Recent years have seen the beginning of the use of proximity communication such as NFC (Near Field Communication), IrDA (Infrared Data Association), and TransferJet (registered trademark). Users can exchange data between two communication devices by merely performing an operation such as bringing the communication devices close to each other (e.g., see Japanese Patent Laid-Open No. 2007-221355).
Also, the NFC Forum has standardized a protocol for handover from NFC to a different radio communication system such as Wi-Fi (Wireless Fidelity) or Bluetooth (registered trademark).
Meanwhile, there is a communication protocol for searching for services provided by other communication devices and notifying other communication devices of self-provided services (service discovery protocol). Some examples of this include the Simple Service Discovery Protocol (SSDP) and Multicast Domain Name Service (MDNS). Generally, when a service discovery protocol is used over Wi-Fi, several seconds to ten or more seconds is required to discover counterpart devices, and the users need to wait this amount of time between bringing their communication devices close together and finding out whether or not services can be executed, which has the possibility of significantly impairing the usability of the system. To address this, there is a method of using proximity communication to acquire device information regarding services provided by communication apparatuses.
However, in the aforementioned method, in the case where device information has been acquired via proximity communication, and the execution of a service over radio communication has started, it is not possible to detect the disappearance of the counterpart communication apparatus. For this reason, there is a problem in that it is not possible to end the service execution at an appropriate timing.